一、口算。
59 - 7 =
22 + 60 =
6 + 88 =
28 + 40 =
25 - 9 =
25 + 7 =
63 - 4 =
8 + 36 =
66 + 30 =
4 + 29 =
96 - 20 =
60 - 8 =
38 - 6 =
66 - 30 =
33 + 60 =
69 + 3 =
16 - 8 =
92 - 60 =
86 - 40 =
41 - 7 =
32 + 50 =
35 + 30 =
78 - 20 =
74 - 9 =
64 - 9 =
42 + 30 =
95 - 30 =
72 + 6 =
60 + 35 =
39 + 6 =

1. 52
2. 82
3. 94
4. 68
5. 16
6. 32
7. 59
8. 44
9. 96
10. 33
11. 76
12. 52
13. 32
14. 36
15. 93
16. 72
17. 8
18. 32
19. 46
20. 34
21. 82
22. 65
23. 58
24. 65
25. 55
26. 72
27. 65
28. 78
29. 95
30. 45

二、把加法算式改写成乘法算式。
$3+3+3=(\quad)×(\quad)$
$6+6+6+6+6=(\quad)×(\quad)$
$5+5+5+5=(\quad)×(\quad)$
$2+2+2+2+2+2=(\quad)×(\quad)$
$4+4+4+4+4=(\quad)×(\quad)$
$8+8+8+8+8+8+8=(\quad)×(\quad)$
$7+7+7+7+7+7+7+7+7=(\quad)×(\quad)$

1. 3×3
2. 6×5
3. 5×4
4. 2×6
5. 4×5
6. 8×7
7. 7×9